All About Cavities 2

How Your Teeth Decay
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The bacteria in your mouth need food to live and multiply. When you eat sugary foods and other carbohydrates, the bacteria use them as food, too. The bacteria then produce acids that can dissolve tooth enamel (outer layer of the tooth).

It's not just candy and ice cream we're talking about. All carbohydrate foods eventually break down into simple sugars. These include glucose and fructose. Some of this process begins in the mouth.

Foods that break down into simple sugars in the mouth are called fermentable carbohydrates. These include the obvious sugary foods, such as cookies, cakes, soft drinks and candy. But they also include pretzels, crackers, bananas, potato chips and breakfast cereals.

Bacteria in your mouth turn the sugars in these foods into acids. These acids begin to dissolve the mineral crystals in teeth. The more times you eat each day, the more times your teeth are exposed to an acid attack.

This attack can lead to tooth decay, also known as dental caries. First, the acid begins to dissolve calcium and phosphate crystals inside a tooth. A white spot may appear on the enamel in this weakened area. But the loss of minerals develops beneath the surface of the enamel. The surface may still be smooth.

At this stage, the tooth can be repaired with the help of fluoride, proteins and minerals (calcium and phosphate) in the saliva. The saliva also helps reduce the acid levels from bacteria that attack the tooth.

Once the decay breaks through the enamel to cause a cavity, the damage is permanent. A dentist must clean out the decay and fill the cavity. Left untreated, the decay will get worse. It can destroy a tooth all the way through the enamel, through the inside dentin layer and down to the pulp or nerve of the tooth. That's why it is important to treat caries at a very early stage, when the process can be reversed.